Synergistic herbicidal compositions of ioxynil and buturon



United States Patent 01 3,462,258 Patented Aug. 19, 1969 ice 3 462,258 SYNERGISTIC HERBI CIDAL COMPOSITIONS F IOXYNIL AND BUTURON Gerbert Linden, Peter Schicke, and Hermann Korner,

For the preparation of the herbicidal compositions according to the invention, N-(4-chlorophenyl)-N-methyl I I-isobutynyl-urea was used as a wettable powder conslsting of 50% by weight of the urea compound and the remainder an inert carrier, and 3,5-diiodo-4-hydroxy- Ingelheim am Rhein, Germany, assignors to C. H.

Boehringer 5 1 lngeiheim am Rhein Germany a benzonitrile was used as an aqueous 40% emulsion conli it d t hi centrate, which are customary forms of application.

No Drawing. Filed Nov. 21, 1966, Ser. No. 595,581 The tests were performed and evaluated twice; the re- Clanns priority, appllcatl ll Germany, N 1965, sults of the final evaluation are summarized in Tables I Int (2650 1 900 and US. CL 71 105 n 4 Claims In Table I, the limiting dose (LD90) required for 90% effectiveness is given in liters or kg./hectare of the preparation, and next to this the synergism, calculated ABSTRACT OF THE DISCLOSURE according to the method of Yen-Pei Sun and E. R. Johnson, Journal of Economic Entomology, vol. 53, 887-892, synerglstle hefbleldal eoolposltlons eolltalnlng N'(4 is given, as expressed by the so-called Co-toxicity-coeffio P YU- }Y 3f y e cient (C.T. coefficient). In regard to the combined ef- 10d0-4-hYdFoXYbeI1ZoI11tf11e as aetlve lngl'edlentsfect of the two components, the following meanings pp y:

This invention relates to herbicidal compositions concoefifictentzmo means an additive aotionmining N (4 chlorophenyl) N, methy1 isobutynyl C.T. coeflicient smaller than 100 means an antagonistic urea in combination with 3,S-diiodo-4-hydroxybenzoniaetlont ile as activeingredients C.T. coefficient greater than 100 means a synergistic N-(4-chlorophenyl)-N-1nethy1-N'-isobutynyl-urea and 5 action.

TABLE I Effect on various weeds and stages of development Sinapis Lolium Stellaria Tested dose range, Mixing C.T. O.T. C11, Preparation kg./1./ha. ratio D6 coefficient E4-5 coefiicient D4-5 coefficient; N-(4-chlorophenyl)-N-1nethyl-N- 0. 5-5 4. 2 4. 2 1. 1

isobutynylurea. 3,5-diiodo4-hydroxybenzonitrile 0. -2. 5 0. 4 2. 5 2. 5 N-(4-chl0rophenyl)N-methyl-N- 0. 25-2. 5 1; 1 0.3 115 1. 7 127 0. 4 1 5 isobutynyluIea/3,5-diiodo4- 0. 25-2. 5 0. 3 1. 7 0. 4

hydroxybenzonitrile.

3,5-diiodo-4-hydroxybenzonitrile differ from each other The designations D45, D6 and E4-5, represent the in their herbicidal properties. Upon testing of combinastages of development of the plants, classified according tions of both active substances it was surprisingly found to Bulletin No. 27 of the Biologische Bundesanstalt fiir that these combinations exhibit a strong synergism of Landand Forstwirtschaft (Biological Institue for Agboth activeingredients. riculture and Forestry of the Federal Republic of Ger- Numerous tests with compositions containing varying many). Proportions of the two herbicidal Compounds Were An analogous test on corn and Galium shows the ducted on different Weeds; e the y e g of the o strongly synergistic herbicidal action of the composition bination of the two herbicidal compositions was verified on Galium Galium cannot practically be combated with on grasses and broadleaf Weeds- N-(4-chlorophenyl)-N'-isobutynyl-urea, because in many While N (4-chlorophenyl)N'-methyl-N-isobutynylcases the doses necessary for this purpose prove harmful urea alone has to be used at a rate of 4 kg. per hectare in t0 the agricultural plants. combating broadleaf weeds a combination of 3,5-dii0do- Table II shows the synergistlc herbicidal action of the 4-hydroxybenzonitrile and N-(4-chlorophenyl)-Nrneth- Combination compositions on Gahum. From these reyl-N'-is0butynyl-urea applied at a rate of 1 kgjhectare sults 1t Can be concluded that Gal1um growing among has proved equally eltective. Moreover, the rate of 4 0 agricultural plants can be effectively combated with the kg./hectare of N (4-chlorophenyl)-N'-methyl-N'-isoaid of the combination compositions according to the butynyl-urea lies precariously near the limit of tolerance IIlVeHtlOn. f com Analogous to Table I, Table II indicates the limiting For the experiments corn and weeds were sown for dose q e a effectlveness nd the CT. coefficient. D1 indicates the development phase of the logarithmic test.

Lolium peremze was used as a particularly resistant type of grass.

the plant corresponding to the explanation given for Table I.

No satisfactory results have been attained in combating fox-tail grass (Alopecurus myosuroides) with N-(4- chlorophenyl) N methyl-N-isobutynyl-urea, since the minimum dose lies precariously near the limit of tolerance of cereal grains.

The results shown in Table II indicate the synergistic effect of the compositions according to the invention against fox-tail grass. The test was conducted on Alopecurus myosuroides in the development stage D23. It proved that the composition according to the invention is capable of effectively combating fox-tail grass.

TABLE III [Effect of the test preparation on Alopecurus among beets (herbicidal limiting dose LD 90 in liters or l g./l1ectare preparation and 0.1. coefficient of the combination)] Tested Alopecurus dose range, Mixing C.T. co Preparation kg. /l. /ha. ratio LD90 eflicient 3,5-diiodo-4-hydroxybenzonitrile 0. 5-5 5 N-(4-chlorophenyl) -N-metliyl- N '-isobutynyl-urca 5-5 5 N-(4-ehloropheny1)-N '-methyl- N-isobutyny1-urea/3,5'diiodo 4-l1ydroxybenzonitrile 0. 5-5 2 1 2. 75 235 The above tests proved that combinations of N-(4- chlorophenyl)-N-methyl-N'-isobutynyl-urea and 3,5 diiodo-4-hydroxybenzonitrile have a synergistic effect; in

4 other words, the effectiveness of the combination of the two active ingredients exceeds the additive effect of both components.

Thus, the compositions according to the present invention make it possible to achieve the same herbicidal elTect with substantially smaller doses of the active ingredients. In addition to the reduced cost, the smaller quantities of active ingredients provide significantly improved cereal grain tolerance and a much wider range of application of the herbicidal compositions.

While the present invention has been illustrated with the aid of cerain specific embodiments thereof, it will be readily apparent to others skilled in the art that the invention is not limited to these particular embodiments and that various changes and modifications may be made without departing from the spirit of the invention.

We claim:

1. A herbicidal composition consisting essentially of an inert carrier and a herbicidally effective amount of a mixture of N-(4-chlor0phenyl)-N-methy1-N-isobutynylurea and 3,5-diiodo-4-hydroxybenzonitrile.

2. A herbicidal composition as in claim 1, wherein the weight ratio of the urea compound and the benzonitrile compound in said mixture is from 1:1 to 6:1, respectively.

3. A herbicidal composition as in claim 1, wherein the weight ratio of the urea compound and the benzonitrile compound in said mixture is from 2:1 to 5:1, respectively.

4. The method of killing weeds which comprises contacting said weeds with a herbicidal composition accord ing to claim 1.

References Cited UNITED STATES PATENTS 3,149,955 9/1964 Fischer et al. 71-12.0 3,278,291 10/1966 Evans 71105 3,326,658 6/1967 Harris et al. 71105 OTHER REFERENCES Netherlands application 6,411,452, Apr. 5, 1965, assigned to Amchem 71/ 105.

LEWIS GOTTS, Primary Examiner M. KASSENOFF, Assistant Examiner US. Cl. X.R. 7l120 

